1202 ALARM

I was kindly given a Sony DAT Walkman a few months ago and started playing with it last week. There's a minor issue with it that I will sort out, but it is a solid piece of kit and still working after 30 years. DAT really was the pinnacle of recording technology with full uncompressed 48kHz audio at your fingertips. Now DAT, like MiniDisc, generally has to record and play back at normal speed, so there is no special digital connection for a computer. The Walkman had a proprietary 7-pin digital connection for linking to other digital gear. A quick bit of research revealed that the connectors are as rare as unicorn poo and I couldn't even find a pinout. What I did have though were some optical audio cables and connectors cannibalized from obsolete stereo equipment. I recorded some random audio to a DAT tape and played it back while using the oscilloscope to test the pins in the digital connector. I was able to find a suitable waveform with a 3.3-volt amplitude which l...

Yeah, I've been driving everyone mad about the benefits of MiniDisc over vinyl ever since acquiring a bunch of old MD portables (for free) about 10 years ago, and then finding an MD deck in a charity shop for just £5 last year. Unfortunately it was not a standalone deck, but I picked up the matching amplifer-tuner for just £30 including postage on eBay so that was a bit of a win. A couple of the portables are Sony NetMD units which can link directly to a computer via a mini-USB cable. Some Wizards of the Internet ported the Linux MD software online as Web MiniDisc Pro, which runs entirely in your browder (as a PWA if you know what that means). Copying a CD to MD is a piece of cake, but what I discovered a couple of days ago is that you can also go the other way and rip pre-recorded MiniDisc albums to MP3. I have picked up a few of these free, cheap and not-so-cheap and have gone for albums I do not have on CD (why bother with that?), so this means I can play those albums in the car...

I've been planning getting the Toyota MR2 back on the road and one of the things I have been messing with for the last 20 years is getting a decent sound system without breaking the bank. The MR2 originally had the front speakers in the dashboard with an optional subwoofer under one of the seats, but the dash just doesn't provide enough baffle for a decent sound. In 2010 I built this speaker cabinet which sits between the seats and provides pretty good sound along with 'flux capacitor' visual effects! I have since recovered 2 of these weird speakers from a high-end plasma television I stripped out. The sound quality is frankly amazing for the size of the units. The internal baffle and reflex design is excellent. I want to see if these could be either fitted inside the doors or mounted as pods on the doors themselves. To go with these I need a subwoofer which can either fit under or behind the driver's seat and this little one came my way. It was part of a Hitachi s...

The Office. A facility based on change. (Robert Propst, 1968) Ministry of Justice. 102 Petty France, London SW1H 9AJ. Fitzroy Robinson & Partners in collaboration with Sir Basil Spence. 1976. Action Office II. Designed by Propst/Nelson 1970. Manufactured and marketed by Herman Miller of Zeeland, Michigan.

I have a couple of 20 LED solar strings in the tiki bar at the back of the house. After a couple of years outside the strings weren't working so well and opening up one of the solar panel units I found the AAA NiCd cell inside was only holding 0.5 volts instead of 1.2 volts when fully charged. Initially I went to a few shops looking for direct replacement strings but couldn't find any. Then in Home Bargains I found 50 mini LED strings with larger solar panels and a lithium-ion battery for only £3. So I bought 2 of these and chopped off the LED strings as I was only interested in the solar panel units. An initial test with just twist-and-tape wiring proved this upgrade would work. The next step was to take the solar panel units apart and solder the wiring for my LED strings in properly. I decided to mount the solar panel units under the composite roof to keep them dry so that hopefully they will last a few years longer than the ori...

Another garden power tool converted to run on Parkside/Lidl 20v lithium-ion batteries. This is a nice brush cutter from Ozito which had seen good service on an allotment, but had a failed 18v battery pack. I took the same approach as with the Bosch conversion and gutted the cells out of the battery pack and attached a Parkside adaptor plate. Interestingly, of the 5 cells (18650) in the Ozito battery pack, 4 are serviceable and only 1 had failed, just the same as the laptop batteries. It is working well and I still have 2 adaptor plates from my last AliExpress order for more shenanigans.

A few months ago I bought a mini electric chainsaw from Lidl to cut up wood for the stove. Going by the reduced gas bills I think the chainsaw has almost paid for itself. The chainsaw uses the Parkside 20-volt lithium-ion batteries and I bought a 4Ah battery and charger to run it. Since then I have bought a couple of other Parkside gardening tools and a larger 8Ah battery which was on offer. In all I've spent about £60 on the batteries so I want to get maximum use out of them. Now over the last few years I've acquired free or for a couple of quid, several Bosch drills. These are the last of the tools that used NiCad battery packs. The big SDS hammer drill above came with two 24-volt NiCad battery packs, one completely dead and the other almost dead. I bought a couple of 18-volt NiCad packs to run this and a smaller Bosch drill and they have been really useful, especially last summer when I was working on improving the patio lean-to. So could the Bosch dr...

ELECTRONICS UPCYCLING FAQ CHECK OUT THE OTHER POSTS ON THIS BLOG FOR DETAILS ON REPAIRS AND UPGRADES GOING BACK OVER 10 YEARS - What's the story? I've been tinkering with circuits for over 40 years and have an MSc in microelectronics, and a few years ago realised I could combine this with saving the planet. Basically I'm Greta Thunberg with a soldering iron. - Saving the planet? Well every electronic item kept out of landfill reduces the amounts of dangerous 'forever chemicals', getting released into the environment. By repairing items or stripping out most of the reusable parts this reduces what ends up in landfill and ensures the components go into the correct recycling bins, such as hard plastic cases. - Don't the council do that? Up to a point, but information has emerged about huge amounts of European electronic waste being shipped to Africa and Asia where it continues to damage the environment and people's health, especially the women paid ...

These nice Sony headphones came in another batch of stuff from a kind Freegle user. One of the drivers (speakers) seemed to have burned out and the earmuffs were badly worn. I had a poke in the spares box labelled 'Speakers & Sounders (Small)' and found a pair of Sennheiser drivers that were the same size. The Sony ones were built into the headphone housing, but were easy to dismantle and the Sennheiser units fitted right in. It was just a matter of soldering the cables in and they were not only repaired, but upgraded. I measured the earmuffs to be 70mm and ordered replacements for $3 on AliExpress. The headphones are light and comfortable, but have the great Sennheiser sound quality. Job done.

I found this project while I was experimenting with the NTSC Color video generator some time ago, but finally got round to ordering the parts I needed recently. Thanks to Grant Searle for the awesome work on the project, which seems to have slipped into the recesses of the internet. This may be because unlike the classic 'TV_Out' for the Arduino, you need a programmer to upload the hex file directly to microcontroller. The circuit uses a 74HCT166 parallel in/serial out shift register, clocked at the same 16MHz as an ATmega328P microcontroller, giving the speed necessary for a 640x200 pixel display. The biggest problem I had was with the ATmega328P ICs I bought on Aliexpress. These seemed to have the option fuses set for a slow internal clock and it took a bit of messing about to get the fuses cleared so they could be set for the external crystal. Best of all, data is input via a standard I2C 2-wire interface which will connect to PIC microcontrollers (which I have ...

A kind Freegle user gave me a big collection of vintage home computer equipment a few months ago including 4 48K ZX Spectrums in various states. The photo above shows one of them connected via the aerial RF socket as a test. The random pattern is a typical ssymptom of failed memory ICs.  The first job was to examine the main boards in each of the 4 computers. 3 were Spectrum+ units in the bigger case with the better keyboard and 1 was the classic Spectrum with the rubber keyboard. Unfortunately the classic's case was in very poor condition, but 2 of the 4 main boards were suitable for restoration along with at least 2 of the Spectrum+ cases. The 7805 regulator is a linear type and generates a lot of waste heat, hence the big heatsink. These can be easily replaced with a high-efficiency TSR1-2450 swich-mode type so that the heatsink can be done away with. The next job is to modify the RF modulator to output composite video. This just r...

I bought this Tecknet dual SATA external hard drive dock a few years ago and it's been very useful when I've been upcycling laptops, particularly for cloning one drive to another. The source drive goes in the A slot and the target drive in the B slot, press the clone button on the front and the unit does the rest.  The target drive must be blank and have the same or a larger capacity than the source drive. If the source is bootable then the target will be too. The only issue is that unless the drives are identical in size, the target will have a primary partition the same size as the source followed by unallocated space. This is easily fixed by using GParted to expand the primary partition to fill the whole drive. The unit has a USB 3.0 connection so also invaluable for backing-up prior to upgrading Linux Mint.

I haven't used my remaining Raspberry Pi 2 for a while, but dug it out recently. I had to update the operating system which now has options for over-clocking the CPU to 1GHz as long as you can cool it so there is also an option to run a fan.  The miniature 5v fan recovered from a broken laptop super glued onto a miniature heat sink recovered from a Sky+ box. Prototyping the control circuit using a BS170 MOSFET with the gate connected to GPIO pin 14. Using pin 14 puts the 3 connections in a row (+5v/GND/GPIO14) on the RPi GPIO connector making for easy fitting. The circuit constructed on a piece of stripboard with a recovered 3-pin connector from some long dead piece of kit. The completed fan on top of the RPi's Broadcom CPU with a drop of thermal paste between them. So I enabled the fan and over-clocking and ran the Pi for 2 hours running YouTube videos and a spreadsheet. A little faster but the fan never came on! Seems the heat s...

I was given this really nice HP 350 G2 laptop by a very kind lady on Freegle. As is usually the case it was running slow under Windows. I offered to install Linux, but she had bought a new laptop and just wanted this one to be used. This is the first 15w laptop I've worked on and it needs low power RAM (1.25v), which I didn't have in stock, so I purchased a 4Gb module on eBay for under £5 delivered. This took the total memory to a respectable 8Gb. A 512Gb SSD upgrade (under £20, AliExpress) and a clean install of Linux Mint and I have a decent laptop to do me for the next 3 years. Performance is fine for my needs (mostly web browsing, Zoom and some hobby coding). The CPU is an i5-5200 which seems to be the fastest that the motherboard can handle so I won't be changing the CPU this time. HP Pavilion G6 CPU Upgrade As I usually do, I'm going to cycle my i7-3632M HP Pavilion G6 (above) into the workshop, which will leave two older laptops to pass on via...

This is the big daddy of power banks! 21 18650 cells so the equivalent of 3.5 laptop batteries. Somewhere in the region of 200Wh give-or-take as the cells are used. This one is the easiest to use, spring contacts and a sliding lid. It supports fast charging both in and out at 5, 9 and 12 volts and has a range of USB connections as well as an Apple one. I fully charged it about a week ago and it is showing 96% currently which would indicate 1 or 2 cells cross-charging. When it hits 90% I'll test each cell, identify the weak ones and replace.

I was given this older Apple iPad a while back and was looking into installing Linux on it. Options are limited, but it is possible to install a shell to the iPad and run command line stuff.  SSH is always a bit of fun so I logged into my Linux Mint laptop remotely for a giggle. It was interesting running a few simple commands from the iPad. My cheapo Bluetooth keyboard came in very useful although I discovered that the iPad's OS version predated mouse support so the trackpad didn't work. Going a step further, I got my Raspberry Pi going again and was able to install VNC on the iPad and remotely control the Raspberry Pi's desktop. Could be useful! I'm also looking at fitting a small heatsink and 5-volt fan (recovered from a broken laptop) to the Raspberry Pi and over clocking it to 1GHz.